Classifier



April 3, 1934 A.-

DAMAN' 5 6 CLASSIFIEB Original Filed June 25, 1928 2 Sheets-Sheet l A. C. DAMAN April 3, 1934.

CLASSIF IER Original Filed June 25, 1923 2 Sheets-Sheet gwumiw H5772? C MX Patented Apr. 3, 1934 UNITED- STATES PATENT OFFICE Application June 25, 1928, Serial No. 288,014 Renewed August 3, 1931 31 Claims. (Cl. 209-161) This invention relates to a classifier of the type employed in the milling of ores and the like, for separating the heavier and coarser particles from the fines, slimes and gangue. Classifiers of this type employ water for washing the slimes from the heavier particles and are objectionable because of the great amountof water necessary for their operation.

The principal object of this invention is to provide a classifier which will reduce the amount of water usually required and which will employ the slime solution to assist the incoming water in washing the coarse heavy particles.

Another object of the invention is to subject the pulp to a vibratory motion while in the solution so that the coarser particles can be more efficiently washed and classified.

A further object is to provide a mechanism which will operate mechanical rakes in combination with an impeller so that the solution in the classifier will be used to wash the raked material.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efiiciency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views of the drawings and throughout the description.

In the drawings:

Fig. 1 illustrates a cross section through one form of my improved classifier.

Fig. 2 is a horizontal section therethrough taken on the line 2-2, Fig. 1.

Fig. 3 is a detail section through the impeller and its housing.

Fig. 4 is a fragmentary horizontal section taken on the line 4-4, Fig. 1.

Fig. 5 is a detail cross section through an alternate form of the invention.

Fig. 6 is a plan view of the impeller employed in the alternate form of Fig. 5.

The invention comprises a tank 10, which may have a, fiat or conical bottom, the conical bottom being illustrated. Surrounding the tank 10 is a slime launder 11. Projecting below the bottom of the tank 10, a classifying compartment 12 is arranged, from which the heavy or coarser particles are discharged through a discharge nozzle 13, controlled by any suitable gate valve The bearing 15 supports a rotatable rake sleeve 16, which is rotated by means of a worm wheel 17 or in any other suitable-manner. The rake sleeve 16 carries a series of rake bars 18 project.- ing from a collar 43 thereon. Each of the rake bars carries a plurality of diagonally placed rakes 19, arranged so that rotation of their rakesleeve 16 will cause them to pass material to- Ward the classifying compartment 12.

A cylindrical feed chamber 20 is fixedly suspended about the rake sleeve 16. As illustrated, this feed chamber is supported from the bearing 15 on brackets 21 and may be adjusted by moving bolts 45 and for screws 46. It may, however, be supported in any desired manner such as by cross braces in the tank 10. The feed chamber terminates immediately above the rake bars 18. The material to be classified is fed into the feed chamber 20 from a suitable chute 22. An impeller shaft 23 is supported in a step bearing 24 within the trunnion of the worm wheel 17 and extends downwardly through the rake sleeve 16, for the support of an impeller 25.

The impeller 25 has angular-1y turned blades, as indicated in Fig. 1, designed to force the solution upwardly as the impeller rotates. The impeller is of the semi-shrouded type being provided with a bottom plate 34. A stiifening bearing 44 can be provided within the rake sleeve to maintain the shaft 23 in a concentric position. It will be noted that there are no bearings in the device below the solution line. The shaft 23 can be rotated from a suitable belt or rope wheel 42.

The impeller 25 is contained within a panshaped impeller housing 26. A perforated diaphragm 27 of rubber or similar material closes the top of the impeller housing 26 and may be clamped in place thereon by means of a clamping ring 28. The diaphragm 2'7 is provided with a relatively large central opening 29 surrounding the shaft 23. Water can be fed through the bottom of the housing 26 by means of a feed water pipe 30 which terminates in a nozzle 31 extending within a depression 32, in the bottom of the impeller 25 as shown in Fig. 3. Additional water can be fed through a perforated cross pipe 33 adjacent the bottom of the classifying chamber 12.

In operation, the worm'wheel 1'7 is rotated at a very slow speed, that is, a fraction of a revolution per minute. The impeller shaft 23 is ro tated at a relatively high speed so that, it will impart a centrifugal action to the impeller. In operation the tank 10 is kept filled so that the solution will overflow into the slime 'launder 11. The pulp to be treated fiows through the chute 22 into the solution and into the feed chamber 20.

The heavy particles settle immediately to the diaphragm 27 where they meet the upwardly flowing currents emanating from the perforations in the diaphragm. These currents and the vibration of the diaphragm wash away any clinging slime and work the particles toward the outer edges of the diaphragm where they will fall to the bottom of the classifying compartment. The rotation of the impeller vanes below the flexible diaphragm imparts a constant undulating vibration thereto which assists in separating and forcing the heavy particles toward the. periphery.

At the bottom of the classifying chamber 12 the particles meet still other currents of fresh water from the cross pipe 33 which give them a final washing before they are discharged through the gate valve 14.

The lighter particles which are not fine enough to be classified as slimes are forced upwardly by the current from the impeller into the tank 10 where they meet a quiescent zone of solution and gradually settle to the tank bottom. They are then slowly raked to the classifying chamber by the rakes l9 and fall along the interior faces of the classifying chamber and are washed by the upwardly flowing currents from the impeller as they travel to the bottom.

It will be noted that the major part of the washing is done by the tank solution itself so as to lessen the amount of water usually required in a hydraulic classifier. I

The light colloidal slimes and fines overflow with the solution into the slime launder 11. A portion of the higher strata in the solution, from which the heavy particles have settled, is drawn through openings 35 in the rake sleeve and flows downwardly therein through the opening 29 into the impeller housing 26. The openings 35, may, if desired, be protected by a shield 36 to prevent the heavy particles which are settling in the solution from being drawn into the openings. This slimy solution is forced by the impeller through the perforations in the diaphragm 27 and assists in washingthe descending heavy particles.

' Additional water can be supplied in the impeller housing 26 by means of the water pipe 30 to assist in the washing, should the slime solution become unduly thick.

In the alternate form of the invention shown in Figs. 5 and 6, the impeller housing 26 is eliminated and a special type of impeller 3'7, illustrated in detail in Figs. 5 and 6, is employed. This impeller is provided with a series of discharge nozzles 38 and is open, as shown at 39, adjacent the impeller shaft so that the slime solution descending in the rake sleeve 16 flows directly into the interior of the impeller and is discharged by centrifugal action through the nozzles 38 against the downwardly flowing pulp. Water can be admitted to the interior of the impeller 3'7 through a water pipe 40 which passes into an opening 41, in the bottom of the impeller.

The operation of the alternate form is similar to that of the first described form. The settling coarse heavy particles-are constantly washed by the streams of slime laden solution from the nozzles 38 as they settle into the bottom of the classifying compartment 12. I 2

It will be noted that there are no frictional contacts below the solution level in the tank in either form of the invention so that excessive wear is eliminated.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invenion.

Having thus described the invention, what I claim and desire secured by Letters Patent is:-

1. A classifier comprising: a solution tank; a shaft within said tank; an impeller carried by said shaft and adapted to move solution upwardly in said tank; a sleeve; spaced from and surrounding said shaft; said sleeve terminating above said impeller and being provided with openings to allow the solution in said tank to flow therein; rakes secured to said sleeve and extending adjacent the bottom of said tank; and means for rotating said sleeve independently of the rotation of said shaft.

2. A classifier comprising: a solution tank; a shaft within said tank; an impeller carried by said shaft and adapted to move solution upwardly in said tank; a sleeve spaced from and surrounding said shaft, said sleeve terminating above said impeller and being provided with openings to allow the solution in said tank to fiow therein; and a feed chamber surrounding said sleeve and opening to the solution below the level thereof.

3. A classifier comprising: a solution tank; a shaft within said tank; an impeller carried by said shaft and adapted to move solution upwardly in said tank; a sleeve spaced from and surrounding said shaft, said sleeve terminating above said impeller and being provided with openings to allow the solution in said tank to fiow therein; rakes secured to said sleeve and extending adjacent the bottom of said tank; means for rotating said sleeve independently of the rotation of said shaft; and a stationary feed chamber surrounding said sleeve and terminating above said rakes.

4. In a classifier having a settling tank; a shaft extending into said tank; a rotary impeller on said shaft adapted to move the tank solution upwardly, a housing surrounding said impeller; and a perforated diaphragm extending across said housing above said impeller, said housing being spaced from the walls of said tank so that material may settle about said housing into the bottom of said tank.

\ 5. A classifier comprising: a bowl-shaped tank; a concentric chamber in the bottom of said tank; a shaft extending into said tank and into said chamber; an impeller carried on said shaft within said chamber and arranged to impart an upward flow to said solution adjacent the walls of said chamber and a downward flow adjacent said shaft; and a rotatable sleeve surrounding said shaft; rakes operated from said sleeve so as to rake material from said tank into said chamber. 6. A classifier comprising: a bowl-shaped tank; a concentric chamber in the bottom of said tank; a shaft extending into said tank and into said chamber; an impeller carried on said' shaft within said chamber; a rotatable sleeve surrounding said shaft; rakes operated from said sleeve so as to rake material from said tank into said chamber; and a feed. chamber surrounding said sleeve and arranged to discharge material toward said impeller, there being openings communicating through said sleeve with said feed chamber.

'7. In a classifier having a settling tank; a classifying chamber formed in the bottom of said tank; an impeller mounted over said chamber; a

shaft for said impeller; rakes arranged to scrape material from said tank into said chamber; a hollow shaft supporting said rakes and surrounding said first shaft; a bearing for said hollow shaft; and a bearing for said first shaft, said latter bearing being supported on said hollow shaft from said first bearing.

8. In a classifier having a settling tank; a chamber in the bottom of said settling tank; a perforated diaphragm arranged in said chamber, spaced from the walls thereof; means for vibrating said diaphragm so that material will be shaken off the periphery thereof, said means comprising an impeller adapted to rotate below said diaphragm so as to also act to force solution through said perforations, said diaphragm having a central opening to allow material to reach said impeller from said settling tank.

I 9. In a classifier having a settling tank; a central vertical shaft in said tank; an impeller actuated by said shaft; a first sleeve concentrically surrounding said shaft so as to direct solution from said tank toward said impeller; a second sleeve surrounding said first sleeve; and means for feeding material to be treated into said second sleeve, all of said sleeves terminating above said impeller.

10. In a classifier having a settling tank; a central vertical shaft in said tank; an impeller actuated by said shaft; a first sleeve concentrically surrounding said shaft so as to direct solution from said tank toward said impeller; a second sleeve surrounding said first sleeve; and means for feeding material to be treatedinto said second sleeve, all of said sleeves terminating above said impeller; and radially extending rake bars carried by said first sleeve and arranged to transport material along the bottom of said tank.

'11. A classifier comprising: a settling tank; a classifying compartment depressed in the bottom of said tank; a pan-shaped impeller housing supported in said compartment and spaced from the walls thereof; a vertical shaft extending into said housing; an impeller carried on said shaft within said housing and arranged to direct material upwardly into said tank and allow heavier material to pass downwardly into the bottom of said chamber around the spaced away housing.

12. A classifier comprising: a settling tank; a classifying compartment depressed in the bottom of said tank; a pan-shaped impeller housing supported in said compartment and spaced from the walls thereof; a vertical shaft extending into said housing; an impeller carried on said shaft within said housing and arranged to direct material upwardly into said tank and allow heavier material to pass downwardly intothe bottom of said chamber aroundthe spaced away housing; and a perforated diaphragm closing the top of said panshaped housing, said diaphragm having an intake opening adjacent said shaft so'as to allow material to flow from said tank into said housing.

13. In a classifier having an overflow, mechanical means to produce an upward current in a slime solution in opposition to the downward movement of settling solids in the solution, the classifier having an imperforate settling surface arranged out of the direct line of said current, a perforated surface above said means, spaced from a wall of the classifier to provide a passage for settling solids to a chamber in the classifier beneath said surface, and a rake-element to move settling solids over said surface in the classifier to the passage.

14. In a classifier having an overflow for slimes in a slime solution, a rotary impeller element adapted to produce an upward current in the solution in opposition to the movement of solids settling out of the solution, a conduit-element directing solution matter to a point in the solution above the impeller, there being a chamber for settling solids beneath the impeller, a passage for solids from above the impeller to the chamber, and a rake element for moving settling solids over a surface in the classifier, to the passage.

15. In a classifier having an overflow for slimes in a slime solution, a rotary impeller element adapted to produce an upward current in the solution in opposition to the movement of solids settling out of the solution, a feed pipe, a rake element, a shaft for the impeller element and a tubular shaft for the rake element, concentrio with the shaft of the impeller element and the feed pipe, the tubular shaft communicating with the feed pipe to receive the feed.

16. In a classifier having an overflow for slimes in a slime solution, a rotary impeller element adapted to produce an upward current in the solution in opposition to the movement of solids settling out of the solution, a conduit having openings for the conveyance of the upper strata of the solution to a point above the impeller, there being a chamber for settling solids beneath the impeller, and a passage for solids from above the impeller, to the chamber, and a rake element for moving settling matter along a surface in the classifier, to the passage.

1'7. In a classifier having a settling tank, a chamber in the bottom of said settling tank, a perforated diaphragm arranged in said chamber, spaced from the walls thereof, and means for vibrating said diaphragm so that material will be shaken off the periphery thereof.

18. A classifier comprising a container for slimes and the like, means for feeding to the container material containing particles adapted to settle in the slimes, a rotary impeller in the container adapted to cause an up-current coun ter to the settling action, a shaft for the impeller, a sleeve around the shaft and a feed chamber around the sleeve, the sleeve and chamber being connected to receive slimes from the container, said means feeding material to .the chamber, and the sleeve having openings for the passage of feed material from the chamber to the interior of the sleeve, the sleeve terminating adjacent to the impeller.

19. In a classifier having an overflow determining a liquid level, a feed chamber extending into the classifier below the liquid level, and a rotary impeller disposed to draw feed material down through said chamber" and to cause an upwardly directed current of the feed material outside the same, there being a settling compartment below the impeller, and a passage past said impeller for conveying settling solids into said compartment out of said current. I

20. In a classifier having a slimes overflow, means in the classifier to produce an upward current in a slime solution in opposition to downward movement of settling solids in the solution, the classifier having a relatively quiet zone beyond the sphere of influence of the upward currents, for settling solids out of the solution, a settling surface beneath. the same, and a chamber for settled solids below the surface, a housing for said means spaced from the wall of the classifier to provide a passage for material passing from said settling surface to said chamber and disposed to define a plane of separation between the zone ofthe upward currents and the final settling zone, and a mechanical element to move solids from said surface to said passage.

21. In a classifier having an overflow for slimes in a slime solution, a'rotary impeller element adapted to produce an upward current in the solution in opposition to the movement of solids settling out of the solution, and a conduit having openings for the conveyance of the upper strata of the solution to a point above the impeller, there being a chamber for settling solids beneath the impeller, and a passage for solids from above the impeller to the chamber.

22. In a classifier having a slimes overflow and a chamber to receive solids settling out of a slimesolution, a plate of vibratory material providing a settling surface over the chamber, and spaced from the wall of the chamber to provide a passage for solids to the chamber, the plate being mounted for vibration whereby to disturb solids settling upon the surface, and an impeller element to impart such vibration to the plate.

23. In a classifier having a slimes overflow and a chamber to receive solids settling out of a slime-solution, a perforated plate of vibratory material providing a settling surface over the chamber, and spaced from the wall of the chamber to provide a passage for solids to the chamber, the plate being mounted for vibration whereby to disturb solids settling upon the surface, and an impeller element beneath the surface to impart such vibration to the plate, and adapted to produce an upward current in the solution in opposition to the downward movement of settling solids in the solution.

24. The method of separating solids in slimesolutions, consisting in effecting movement of slimes and slimes and sands in separate downwardly directed currents to points of discharge beneath a determinate liquid level, and separating sands from the slimes in the slimes and sands current at a submerged point of discharge whereby the slimes may rise to the liquid level and the sands may settle in the liquid.

25. The method of separating solids in slimesolutions, consisting in effecting movement of slimes and slimes and sands in separate downwardly directed currents to points of discharge beneath a determinate liquid level, and simultaneously effecting an upwardly directed air outrent in the solution whereby the slimes may rise to the liquid level while the sands may settle in the liquid.

26. The method of separating solids in slim solutions, consisting in effecting movement of slimes and slimes and sands in separate down: wardly directed currents to points of discharge beneath a determinate liquid level, and simultaneously efiecting an upwardly directed current in the solution whereby the slimes may rise to the liquid level while the'sands may settle in the liquid.

27. In a classifier having a slimes overflow and a chamber to receive solids settling out of a slimesolution, a plate of vibratory material providing a settling surface over the chamber, and spaced from the wall of the chamber to provide a passage for solids to the chamber, the plate being mounted for vibration whereby to disturb solids settling upon the surface, and an impeller element adapted to eject air into the solution in an upwardly directed current.

28. In a classifier having an overflow determining a liquid level, a feed chamber extending into the classifier below the liquid level, means disposed to draw feed material down through said chamber and to cause an upwardly directed current of feed material and air outside the same, there being a settling compartment below the means, and a passage past said means for conveying settling solids into said compartment against said current.

29. A classifier comprising a tank having an overflow determining a liquid level therein and having a compartment centrally of its bottom portion and a settling surface exteriorly of same, an agitating element in said compartment to impart an upward thrust to material under treatment thereby producing a zone of agitation centrally of the tank and around the same a zone of comparative quiescence above said settling surface, and a rotary element in the quiescent zone for moving settled material to said compartment for its gravitational movement in said compartment adjacent to but beyond the sphere of influence of said zone of agitation.

30. A classifier comprising a tank having an overflow determining a liquid level therein and having a compartment centrally of its bottom portion and a settling surface exteriorly of same, an agitating element in said compartment to impart an upward thrust to material under treatment thereby producing a zone of agitation centrally of the tank and around the same a zone of comparative quiescence above said settling surface, a rotary element in the quiescent zone for moving settled material to said compartment for its gravitational movement in said compartment adjacent to but beyond the sphere of influence of said zone of agitation, and means in the agitation zone for the return of slimes to the agitating element.

31. A classifier comprising a tank having an overflow determining a liquid level therein and having a compartment centrally of its bottom portion and a settling surface exteriorly of same, an agitating element in said compartment to impart an upward thrust to material under treatment thereby producing a zone of agitation centrally of the tank and around the same a zone of comparative quiescence above said settling surface, a rotary element in the quiescent zone for moving settled material to said compartment for its gravitational movement in said compartment adjacent to but beyond the sphere of influence of said zone of agitation, and a source of water supply in said compartment beneath the agitating element to subject the falling material to further washing.

ARTHUR C. DAMAN. 

